Respiratory exerciser



FIG. 1 is a perspective view of a respiratory exerciser embodying our new design with the hose and a user shown in phantom lines for purposes of illustration only.

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a front elevational view thereof; and

FIG. 4 is a rear elevational view thereof. 

The ornamental design for a respiratory exerciser, as shown and described. 